#!/usr/bin/env python
#coding:utf8

def read():
    p, q = map(int, raw_input().split())
    p = 0.01 * p
    q = 0.01 * q
    return p, q


def rec(cur, p, q, ans):
    if cur < 1e-9:
        return

    # 必勝法を使って勝つ
    ans[0] += p * cur * 0.5

    # 必勝法を使ってあいこになる
    rec(p * cur * 0.5, max(0, p - q), q, ans)
        
    # 必勝法を使わず勝つ
    ans[0] += (1 - p) * cur / 3
    
    # 必勝法を使わずあいこになる
    rec((1 - p) * cur / 3, min(1, p + q), q, ans)
    

def work((p, q)):
    ans = [0.0]
    rec(1.0 / 3, p, q, ans)
    print "%.10lf" % (ans[0] + 1.0 / 3)


if __name__ == "__main__":
    work(read())